A leader of Mapam in Israel warned yesterday that the extension of the cease-fire to Feb. 5 remains “an uneasy balance or no balance at all” for Israel and that “this new situation (is) a much more dangerous and explosive kind of short-term stalemate.” Yitzhak Patish, former political secretary of Mapam and a member of Kibbutz Kfar Masaryk, told the Fall semi-annual conference of the Americans for Progressive Israel National Council meeting here this weekend that “no responsible Israeli leader can underestimate the difficulties and the blatant dangers of a cease-fire without peace talks.” Mr. Patish, who has been touring the United States and Canada to discuss the need for peace in the Middle East, declared that it is “a vain hope or a flat delusion to count on the cease-fire line to go unchallenged to the extent that it becomes a real frontier.” In view of the unprecedented heavy Russian military involvement in the Mideast, “everyone has to perceive the Damoclean character of confronting a well-oiled military machine.” Mr. Patish told the API, a Socialist-Zionist organization which supports Mapam’s point of view, that the bulk of Israel’s population are fed up with the “adventurist slogans” of those who oppose any withdrawal from occupied territories and are exerting pressure for “an Israeli peace initiative.”